Multistep pulley



J1me 1952 A. FRIEDMAN EIAL MULTISTEP PULLEY Original Filed Jan. 24, 1946 Hrflgur Friedman nvmvmxs. LOlllS Silber Patented June 10, 1952 MULTISTEP PULLEY Arthur Friedman, Cleveland, Ohio, and Louis Silber, deceased, late of Cleveland, Ohio, by. Ruben Silber, administrator, Cleveland, Ohio, assignors to Air Controls, Inc'., Cleveland, Ohio, a corporation of Ohio Substituted for abandoned application Serial No. 643,067, January 24, 1946. This application November 28, 1951, Serial No. 258,592

7 Claims. (Cl. ii-230.17)

This application is a substitute for application Serial No. 643,067, filed January 24, 1946, now abandoned.

Our invention relates to pulleys for variable speed drives.

An object of our invention is to provide an improved, simply constructed, rugged pulley for V-belts which is adjustable in effective diameter. A further object of the invention is to render such an adjustable pulley self-locking and to provide quick, easy adjustment of effective pulley diameter.

Still another object of the invention is to provide a multi-step ratchet type of pulley.

Other and further objects, features and advantages of the invention will become apparent as the description proceeds.

In carrying out the invention in accordance With a preferred form thereof, we provide a pulley with two relatively rotatable parts, each carrying one of the two conical-surface flanges between which a V-belt is intended to ride during operation of the pulley. One of the pulley parts is secured to a drive shaft or driven shaft and the other part has a loose fit on the shaft. One of the parts, preferably the relatively movable part, is formed with an annular ratchet, which has axial lift progressively changing around the periphery of the ratchet; and the other part carries a drive pin adapted to cooperate with the ratchet for limiting the space between the flanges of two pulley parts. Suitable resilient means such as a compression,

spring is provided for holding the pulley parts as far apart as permitted by the engagement between the drive pin and the ratchet. Relative rotation of the two pulley parts, with the drive pin riding over the teeth of the ratchet, serves to adjust the relative axial position of the pulley Fig. 3 is an outside view of the pulley of Fig. 1

in the fully closed or high speed position; and

Fig. 4 is a developed view of the circumference of the ratchet portion of the movable pulley part.

Like reference characters are utilized throughout the drawing to designate like parts.

The form of multi-step ratchet pulley shown in the drawing by way ofillustration, comprises a hub II carrying a fixed pulley part l2 secured to the'hub H and a relatively removable pulley part l3, loosely mounted on the hub l I. The pulley parts l2 and 13 include frusto-conical surface portions or flanges l4 and I5, respectively, forming a tapered or V-shaped sheave or groove NS for receiving a V-belt ll of conventional form. The pulley part I3 is adapted to be moved back and. forth-axially so as to increase or decrease the width of the belt groove 16 whereby the effective diameter of the pulley is varied.

The hub II is adapted to be secured to a shaft [8 inany suitable manner as by means of a keyway 19 and a key or feather 2!. The shaft l8 carrying the pulley, may be either a drive. shaft or a driven shaft. For the sake of illustration, the shaft l8is assumed to be the drive shaft for the variable speed drive, for example, a shaft of an electric motor 25, represented fragmentarily.

The pulley part [2, is secured to the hub II, in any suitable manner. as by means of.a set screw 22. The pulley part [3 makes a loose fit on the hub II and is provided with means for resiliently spreading the pulley flanges l4 and i5. Preferably, the pulley parts I2 and I3 are undercutto formncounterbores 23receiving a compression spring .24 surrounding the central portion of the hub II.

The outer end of the pulley part [3, that is the end away from the drive motor 25 has an annular ratchet 26 formed therein. The ratchet 2B is formed with a plurality of, teeth, preferably relatively evenly spaced around the periphery thereof; but, with progressivelygreater lift measured axially as one progresses around the periphery of the ratchet 26. For example, where six-difi'erent speed adjustments are desired, the ratchet 26 is provided with six teeth, 21, 28, 29, 30, 3| and 32. As illustrated in the developed view, Fig. 4, the tooth 21 has the smallest lift or is the closest to the motor end of the pulley part I3, and the lifts of the teeth 28, 29, 30, 3| and 32 become progressively greater. To cooperate with the ratchet 26 and to limit the extent to which the pulley parts l2 and,l3 are spread. by the compression spring 24, a drive pin 33 is provided which is suitably secured to the rigid part of the pulley. For example, in the arrangement illustrated, it passes through diametrically arranged openings in the hub ll.

Preferably the ratchet teeth 21 to 32 are slightly ratchet teeth 21 to 32, inclusive, are arranged to point in the opposite direction, namely, the-c1ock--- wise direction. Thereby the drive-pin .33 serves; 7 not only to limit the relative-axialmovementlof the pulley parts I2 and I3; .but; -also renders (the: I

pulley adjustment self-locking. The counterclockwise direction of the drive or the motor rotation is represented by thearrow in-Figs. 2V

and 4. Since the ratchet teeth 26 are formed in;

the pulley part l3 and the pin 33iis securedito:

the pulley part l2, the ratchet and pin normally rotate with the pulley to form a self-contained pulley unit. This feature also enables the pulley adjustment to be self-lockingand notto'depend upon external control.

Preferably as a protection-to the ratchet and to operators andto I improve the appearance of 1 the pulley, a'removable end cap 35- is 'provided 'to cover the ratchet 26 and issecured to the-pulley part l3-in any suitable manner as bymeans of screws 36-.

The adjustment of I theeffective pulley diameter is accomplished by grasping-the pulley parts l2 and I3 and'rotating the part [3 counter-clockwise relative to the part I2; To facilitate this operation, the part'l2 is preferably provided with a knurled surface 3l-and the-endcap 35=is pro-' vided with a knurled=surface38;- Asthe ratchet teeth 3|, 30; Hand so onare-causedto'passsuccessively under thedrive *pin 33, the opening be-- the width of the sheave and effective diameter may be adjusted by relative rotation of said drive pin and said ratchet, said drive shaft being adapted to-rotatein a given directionand said ratchet having. teeth pointingin the opposite direction, whereby the adjustment is rendered self-locking when said drive shaft rotates in said given direction.

2; An adjustable pulley comprising in combination ahub, a pulley part secured thereto, a secondp i-lleypart movably mounted on the said hub', saidpulleyparts having confronting frustoconical-surfaces-toform a sheave for a V-belt, a compression-spring for resiliently separating the said-pulley parts; a'pin extending radially from said hub, said second pulley part having an annular ratchet formed to engage said pin, aid ratchet having an axial lift increasing along the periph-. ery ofsaidratchet for enabling the width of the sheave and effective pulley diameter to be varied by relatively rotating saidhub and said movable pulley part;

3. An adjustable pulley comprisingcincombina tion apair of relatively movable pulleypartsha'vtween the flanges l4 and -I 5'ispermitted'to'becomegreater and greater, so that the effective pulley diameter decreases sincethelbelt I! is permitted to'drop further into the beltgroove l6; However,

after the last tooth 21' has been reached, continued relative rotation of thepulley parts i 2 and l3 forces the pulleyparts together again as'the pin 33 rides along thereturn lift=portion 39 of the ratchet 26... The ratchet teeth 2lto 32--are preferably evenly spaced; but; preferably a greater space is provided -between the ratchet" teeth'21 and 32.

When the motor 25 is started, the pulley locksitself in any adjustment in which it has been set because the drive pin 33 hooks intoone of the ratchet teeth and further-relative rotation of the pulley parts is prevented;

While the invention has been described as embodied in concrete formand as operating in a specific manner in accordance with the provisions of the patent statutes, it should be understood that the invention is not limited thereto; since various modifications will suggestlthemselves; to those skilled inthe art without departing fromthe spirit of the invention, the scope of which is set forth in the annexed claims;

What we claim is:

L An adjustable pulley. comprisingin combina'-' tion a drive shaft, a hub secured thereto, first and second pulley parts having confronting frusto' conical surfaces to form a sheave, the first pulley part being. secured to said. hub, acompression increasing along the periphery thereof, whereby ing confronting frusto-conical surfacesatoform a sheave fora V.-belt, oneof. said pulley parts having anannular ratchet formedltherein withcsuccessive teethaxially displaced with respect to. eachother, a .pin secured to the other of. said pulleyparts and extending. transversely to engage. said ratchet, and a spring. for'exerting. an axial:

force between said pulley parts to holdzsaid 'tpin against saidratchet, whereby the width: of: the sheave and the. effective pulley diametenmaybe; varied by relative. rotation of said pulley. parts.

4. An adjustable pulleycomprisingin combina' tion a pair of parts having OOIIflOIltiIIg substan tially frusto-conical surfaces :to form a sheavefor a V-belt', anannular-ratchet secured to one ofr 4m said parts, and-a drive pinto engage said ratchet;

securedto the other of said parts with meansyforfi resiliently biasing said pulleyparts tocause the= pin to bear against the ratchet, whereby thewidth of said sheave and theeffective pulley diameter: maybe adjusted by relative rotation "of said pulley; parts,-and-both ratchet and drive pin normally ro tatewith-the pulley toform a-self-containe'di pulley unit. r

5; Ari-adjustable pu11ey-comprisingjin-combina tion a'pair-of pulley parts havingconfronting: frusto-conical' surfaces to form a sheave: for aw V-belt, ahub to which one of said parts -isse cured; the other being slidableon said hub, ans

annular ratchet secured to one of said partewitl i'i successive teeth axially displacedfrom one aniother; means secured to the other of saidepulley pa-rts'for engaging said ratchet teeth when one:- pulley part tends to drive the other, and meansi forholding theengaging means againstfisaid ratchet, for locking the said pulley parts totrotate'i together on said hub, whereby the width of the sheave-and the effective pulleydiameter'are determined by the relative angular? position: of 'J said pulley parts, and .both the ratchet and1ratchetT-.-

engaging means normally rotate'withithe pulleyi to form a self-containedpully unit: 1

6. An" adjustable pulley" comprising a pair: of pulley; parts having confronting: frusto-conicali surfacesto form a sheave for a:V.'-belt,:a hub' to which one of said parts is secured thelotherbe 'ing 'slidableon said hub, oneiof sai'di-pulley parts being driven when the pulley rotates in a: pre determined direction; an annular ratchet secured to one of 1 said parts with successive -teeth -par tially hooked and axially displaced from one-a11 other, means secured to the other of said pulley parts for engaging said ratchet teeth in opposition to the direction in which said teeth are hooked when one pulley part tends to drive the other for locking the two pulley parts to rotate together on said hub whereby the width of the pulley sheave and the efiective pulley diameter are determined by the relative angular positions of said pulley parts, and both the ratchet and ratchetengaging means normally rotate with the pulley to form a self-contained pulley unit.

7. An adjustable pulley comprising in combination a pair of pulley parts having confronting frusto-conical surfaces to form a sheave for a V-belt, a hub to which one of said parts is secured, the other being slidable on said hub, means secured to one of said parts with angularly spaced teeth successively displaced axially from one another, and means secured to the other of said pulley parts for engaging said teeth when one pulley part tends to drive the other for locking the two pulley parts to rotate together on said hub, whereby the width of the pulley sheave and effective pulley diameter are determined by the relative angular position of said pulley parts, and

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 423,266 McGuire Mar. 11, 1890 487,721 DeKalb Dec. 13, 1892 939,427 Main Dec. 13, 1892 2,092,469 Oslund Sept. 7, 1937 1 FOREIGN PATENTS Number Country Date 3,440 Great Britain 1909 23,292 Great Britain 1911 

